Dialkyl-3-acetyl-4-hydroxybenzyl phosphonates

ABSTRACT

METAL MONO-, BIS-, AND TRIS-DERIVATIVES OF PHOSPHONIC ACID HALF-ESTERS USEFUL AS ULTRAVIOLET LIGHT ABSORBERS ARE PREPARED BY REACTING A DIALKYL-3-ACETYL-4-HYDROXYBENZYL PHOSPHONATE WITH AN ALKALI-METAL HYDROXIDE TO FORM THE ALKALIMETAL DERIVATIVE WHICH IS THEN CONVERTED TO THE BIS- OR TRISDERIVATIVE BY REACTION WITH A BI- OR TRIVALENT METAL CHLORIDE.

United States Patent US. Cl. 260946 8 Claims ABSTRACT OF THE DISCLOSURE Metal mono-, bis-, and tris-derivatives of phosphonic acid half-esters useful as ultraviolet light absorbers are prepared by reacting a dialkyl-3-acetyl-4-hydroxybenzyl phosphonate with an alkali-metal hydroxide to form the alkalimetal derivative which is then converted to the bisor trisderivative by reaction with a bior trivalent metal chloride.

This invention relates to novel metal derivatives of phosphonic acid half-esters, their preparation and use as ultraviolet light absorbers. More particularly, the present invention relates to the preparation and use of the novel compounds which may be defined as metal mono-, bis, and tris-[tO-alkyl) 3 acetyl 4 hydroxybenzyl] phosphonates.

It is well known that polymeric organic materials and polymeric organic coating compositions, hereinafter called polymeric organic compositions, tend to undergo deterioration when exposed to ultraviolet light. Light in the ultraviolet portion of the spectrum and particularly that having a wavelength within 290-400 millimicrons causes photocatalyzed changes, such as yellowing and/or embrittlement of unstabilized polymeric compositions. These changes are obviously undesirable and this is particularly true when the composition is initially colorless, transparent, or translucent and is to be used subsequently under conditions that will subject it to long exposure to sunlight or other sources of ultraviolet light radiation. Examples of such applications include translucent roofing materials, transparent structures, decorative structures, decorative and protective coatings, and impact-resistant windows.

In recent years, many organic compounds have become available which can absorb ultraviolet light and convert it to less harmful forms of energy such as heat, vibrational energy, or less harmful radiation. These organic stabilizers, in addition to absorbing ultraviolet radiation in the selected range for the polymeric compositions being treated, must be compatible therewith, have little or no initial color, be reasonably inexpensive, be chemically stable, and have a low toxicity, especially for stabilizing compositions to be used subsequently in the food industry.

There are two main ways in which a compound may act as a stabilizer to prevent polymer degradation by ultraviolet light: (1) It may preferentially absorb most of the incident ultraviolet light and dissipate the associated energy in a harmless manner. In this case, the compound protects the polymer by competitive absorption of ultraviolet light. Products that protect in this manner are commonly referred to as ultraviolet absorbers or as ultraviolet screening agents. (2) It may remove the energy that the polymer has absorbed before photochemical degradation can take place. Products that protect in this manner may be referred to either as energy transfer agents or as excited state quenchers.

We have found that many of the compounds of our invention, particularly the heavy metal complexes are excellent excited state quenchers in addition to their outstanding ultraviolet light absorbing properties. This com- 3,767,735 Patented Oct. 23, 1973 bination of properties in a single compound makes our compounds ideal stabilizers for polymeric organic compositions such as films and fibers having high surface to volume ratios which are very difficult to protect against photodegradation by using a compound that is merely an excellent ultraviolet light absorber.

A good ultraviolet absorber for use in polymeric organic compositions should absorb the ultraviolet radiation in daylight, impart no or very little color to the composition, should be sufliciently stable to withstand curing conditions, and should absorb ultraviolet light sufiiciently to protect the composition against yellowing and decomposition on exposure to ultraviolet light. The compound must have suflicient solubility in various types of materials so that it may be incorporated therein, it should be capable of withstanding leaching action of solvents or loss by exudation.

Generally, an effective ultraviolet absorber should have its peak absorption above a wavelength of 300 millimicrons or the absorption peak may be at a higher wavelength as long as the absorption drops otf sufficiently as it approaches the visual range so that no color is visible. In addition, to be effective it should show a high degree of absorbancy in the desired wavelength range, especially at those wavelengths sufficiently below the visual range so that the compound has no yellow color.

Although, as pointed out above, many compounds have been suggested for the stabilization of polymeric organic compositions against deterioration caused by ultraviolet light, none have been entirely satisfactory as all have been deficient in one or more qualities which the ideal ultraviolet absorber must possess. These include, in addition to lack of color, the abilty to become firmly incorporated in the composition to be stabilized and the ability to absorb ultraviolet light over a wide range. The latter is important because individual polymeric organic compositions are generally most susceptible to deterioration by radiation of a specific wavelength. For example, polyethylene, polypropylene, and polystyrene are susceptible to radiation wavelengths of 300320 millimicrons. Many of the absorbers disclosed in the prior art exhibit excellent ultraviolet light absorption only over a very limited wavelength.

It is, therefore, a principal object of the present invention to provide an ultraviolet light absorber which obviates.

the disadvantages of such absorbers heretofore available.

It is another object of our invention to provide a composition which is resistant to degradation by ultraviolet li ht.

These and other objects and advantages will become apparent as the description proceeds.

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

In brief, the foregoing objects and advantages are obtained by incorporating into a polymeric organic composition susceptible to deterioration by the action of ultraviolet light radiation a compound identified generically as a metal mono-, bis-, or tris-[(O-alkyl)-3-acetyl-4-hydroxybenzyl1phosphonate in an amount varying from 0.1 to about 2.0 percent by weight based on the total weight of the'polymeric organic composition. It is understood, of course, that larger quantities of the phosphdnate may be used, but such is not generally desirable because costs Alternately, these ultraviolet light absorbers may be identified as compounds having the formula:

CH n

wherein R is a straight or branched chain alkyl radical containing from 1 to 18 carbon atoms, M is a metal having a valence of 1 to 3, and n is an integer representing 1 to 3.

Polymeric organic compositions which can be protected from the degrading effects of ultraviolet light by the use of the compositions of our invention include alkyd resins as disclosed in U.S. Pats. 1,847,783, 1,860,164, 1,950,468, and 2,087,852; epoxy resins as disclosed in US. Pat. 2,886,473; polyester resins; polyurethane; polyethylene; polypropylene; polystyrene; polyvinyl chloride resins; cellulosic and acrylic polymers; linear super polyamide obtained by condensing an aliphatic polyethylenediamine with a dicarboxylic acid; industrial coatings including decorative and protective coatings wherein one or more of the components thereof comprises an organic composition susceptible to deterioration when exposed to ultraviolet light; coated fabrics such as fabrics coated with polyvinyl chloride and polyolefin; and polyvinylidene chloride monofilaments.

In order to disclose the nature of the invention still more clearly, the following illustrative examples will be given. It is understood, however, that the invention is not to be limited to the specific conditions or details set forth in these examples, except insofar as such limitations are specified in the appended claims.

In the examples, parts where used are parts by weight.

EXAMPLE 1 Di-(n-butyl)-3-acetyl-4-hydroxybenzyl phosphonate A one-liter, four neck, round-bottom flask equipped with stirrer, condenser, thermometer, and gas inlet was charged with 75.0 grams (0.3 mole) of tri-(n-butyl)phosphite and 55.4 grams (0.3 mole) of 5'-chloromethyl-2- hydroxyacetophenone. The mixture was purged for 5 minutes with nitrogen while stirring and then gently heated to 65-70" C., at which point exothermicity set in and butyl chloride distilled at about 76 to 79 C. The mixture was then heated to approximately IOU-110 at atmospheric pressure to complete the distillation of butyl chloride and then distilled under vacuum to yield the product di-(n-butyl)-3-acetyl-4-hydroxybenzyl phosphonate, B.P. 155 C./0.15 mm.

EXAMPLE 2 Sodium [(O-butyl)-3-acetyl-4-hydroxybenzyl] phosphonate A one-liter, four neck, round-bottom flask equipped with stirrer, reflux condenser, thermometer, and gas inlet was charged with 75.0 grams (0.215 mole) of di-(nbutyl)-3-acetyl-4-hydroxybenzyl phosphonate prepared in Example 1, to which was then added 34.4 grams of a 50 percent aqueous sodium hydroxide solution in 32.5 milliliters of methanol under nitrogen. After five minutes of purging with nitrogen, the nitrogen stream was stopped and the reaction mixture was refluxed 4.5 hours, after which time it was cooled to room temperature and neutralized with concentrated HCl to pH 7 with cooling. The precipitated sodium chloride was removed by filtration and washed with a small amount of isopropyl alcohol. The washing and filtrate were combined and concentrated under reduced pressure. The dry residue was dissolved in a small amount of methyl alcohol and the insoluble solids, identified as sodium chloride, were removed by filtration, The filtrate was evaporated in vacuo Cit 4 to dryness, M.P. 193-195 C. This product was used without any further purification for the preparation of nickel and tin salts.

EXAMPLE 3 Preparation of nickel bis-[(O-butyl)-3-acetyl- 4-hydroxybenzyl] phosphonate A one-liter, three neck, round-bottom flask equipped with stirrer, reflux condenser, and thermometer was charged with 9.2 grams (0.029 mole) of sodium [(0 butyl)-3-acetyl-4-hydroxybenzyl]phosphonate prepared in Example 2 dissolved in milliliters of methanol to which was then added 3.6 grams (0.015 mole) of nickelous chloride hexahydrate dissolved in 20 milliliters of methanol. The reaction mixture was stirred and heated at reflux for a period of one hour, after which it was filtered and the filtrate evaporated to dryness under vacuum. The pale green product did not melt up to 300 C.

Analysis.Calculated for C H NiO P (percent): P, 9.84; Ni, 9.33. Found (percent): P, 9.68; Ni, 9.13.

EXAMPLE 4 Diethyl-3-acetyl-4-hydroxybenzyl phosphonate The foregoing compound was prepared following the same experimental procedure as used in Example 1. In this example, 92.3 grams (0.5 mole) of 5'-chloromethyl- 2-hydroxyacetophenone was reacted with 83.0 grams (0.5 mole) of triethyl phosphite. The crude yellow product obtained was purified by distillation. The colorless liquid obtained as a distillate and identified by its infrared spectrum as diethyl-3-acetyl-4-hydroxybenzyl phosphonate weighed 111.5 grams. This represented a yield of 77.9 percent of theory.

If desired, the reaction may be carried out in the presence of an inert solvent such as benzene, toluene, xylene, or chloroform. This modification of the experimental procedure lessens the vigor of the reaction.

EXAMPLE 5 Sodium (O-ethyl -3-acetyl-4-hydroxybenzyl] phosphonate The foregoing compound was prepared following the same experimental procedure as used in Example 2. In this example, the product of Example 4 (111.5 grams) was reacted with 62.4 grams of a 50 percent aqueous sodium hydroxide solution to produce 68.0 grams of an off-white product identified as crude sodium [(O-ethyl)-3- acetyl-4-hydroxybenzyl]phosphonate. This product had a melting point of 2l0-220 C. and represented a yield of 62.4 percent of theory.

EXAMPLE 6 Nickel bis (O-ethyl -3-acetyl-4-hydroxybenzyl] phosphonate EXAMPLE 7 Di(isopropyl)-3-acetyl-4-hydroxybenzyl phosphonate The same experimental procedure as used in Examples 1 and 4 was used. In this example, 92.3 grams (0.5 mole) of 5-chloromethyl-2'-hydroxyacetophenone was reacted with 104.1 grams (0.5 mole) of triisopropyl phosphite. The reaction can also be carried out in an inert solvent s ch as benzene, toluene, xylene, or chlorobenzene to moderate the vigor of the reaction. The crude product, 142 grams (90.6 percent) was used in Example 8 Without any further purification.

EXAMPLE 8 Sodium (O-isopropyl-3-acetyl-4-hydroxybenzyl) phosphonate The same experimental procedure as used in Examples 2 and 5 was used. In this example, 157.1 grams 0.5 mole) of di(isopropyl)-3-acetyl-4-hydroxybenzyl phosphonate was used with 80.0 grams of 50 percent aqueous NaOH. The crude sodium (O-isopropyl-3-'acetyl-4-hydroxybenzyl)phosphonate so obtained weighed 139 grams, representing a yield of 94.5 percent of theory.

EXAMPLE 9 Nickel bis- (O-isopropyl -3 -acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure of Examples 3 and 6 was followed. In this example, 147.1 grams (0.5 mole) of sodium (O-isopropyl-3-acetyl-4-hydroxybenzyl)phosphonate in 350 milliliters of methanol was treated with 59.4 grams (0.25 mole) of nickelous chloride hexahydrate in 150 milliliters of methanol. The reaction mixture was filtered to remove sodium chloride and the greencolored filtrate was evaporated to dryness under diminished pressure to give a pale green residue weighing 110 grams (73.5 percent yield) which was identified by characteristic peaks in its infrared spectrum as nickel bis-(O- isopropyl 3-acetyl-4-hydroxybenzyl)phosphonate, M.P. 300 C.

EXAMPLE 10 Di isooctyl -3-acetyl-4-hydroxybenzyl phosphonate In this example the experimental procedure of Examples 1, 4, and 7 was followed. Forty-six and one tenth grams of 5'-chloromethyl-2-hydroxyacetophenone (0.25 mole) was treated with 104.6 grams (0.25 mole) of triisooctyl phosphite. After the reaction was completed, the crude di(isooctyl)-3-acetyl-4-hydroxybenzyl phosphonate was used directly without further purification for the preparation of the sodium salt of the corresponding half-ester.

EXAMPLE 11 Sodium (O-isooctyl-3-acetyl-4-hydroxybenzyl)phosphonate The same experimental procedure as used in Examples 2, 5, and 8 was used to treat 114 grams (0.25 mole) of di( isooctyl -3-acetyl-4-hydroxybenzyl phosphonate in 100 milliliters of methanol with 40 grams of 50 percent aqueous sodium hydroxide to give 77 grams (84.5 percent yield) of sodium (O-isooctyl-3-acetyl-4-hydroxybenzyl) phosphonate. This compound was identified by spectroscopic method.

EXAMPLE 12 Nickel bis[ (O-isooctyl) -3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as used in Examples 3, 6, and 9 was used to react 91.1 grams (0.25 mole) of sodium (O-isooctyl-3-acetyl-4 hydroxybenzyDphosphonate with 29.7 grams (0.25 mole) of nickelous chloride hexahydrate. Eighty-three grams (90 percent yield) of nickel bis[(O-isooctyl)-3 acetyl-4-hydroxybenzyl]phosphonate was obtained, M.P. 300" C.

EXAMPLE 13 Dimethyl-3-acetyl-4-hydroxybenzyl phosphonate The same experimental procedure as that used in Examples 1, 4, 7, and 10 was used to treat 184.6 grams (1.0 mole) of 5'-chloromethyl-2-hydroxyacetophenone with 124 grams (1.0 mole) of trimethyl phosphite. This reaction was the most vigorous of all the reactions aimed at the preparation of a dialkyl-3-acetyl-4-hydroxybenzyl phosphonate. The reaction can be moderated by cooling once the evolution of methyl chloride is started. Alternately and somewhat preferably, the reaction may be carried out in an inert solvent such as benzene, toluene, xylene, or chlorobenzene. The product (240 grams, 93 percent) was identified by its characteristic infrared bands as dimethyl-3-acetyl-4 hydroxybenzyl phosphonate and was used without any further purification in the next reaction.

EXAMPLE 14 Sodium (O-methyl)-3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as that used in Examples 2, 5, 8, and 11 was used to treat 240 grams (0.93 mole) of dimethyl-3-acetyl-4-hydroxybenzyl phosphonate was 148.8 grams of 50 percent aqueous sodium hydroxide. One hundred and sixty-four grams (69 percent yield) of a dark brown compound was obtained, M.P. 200-210" C.

EXAMPLE l5 Nickel bis- (O-methyl)-3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as that used in Examples 3, 6, 9, and 12 was used to react 48.5 grams (0.182 mole) of sodium [(O-methyl)-3-acetyl-4-hydroxybenzyl] phosphonate with 21.6 grams (0.091 mole) of nickelous chloride hexahydrate. A green powdery product weighing 43 grams (87.4 percent yield) was obtained and was identified by its infrared spectrum as necked bis[(O-methyl)- 3-acetyl-4-hydroxybenzyl]phosphonate, M.P. 300 C.

EXAMPLE 16 Aluminum tris- (O-ethyl -3-acetyl-4-hydoxybenzyl] phosphonate A SOD-milliliter, three neck, round-bottom flask was charged with 29.7 grams (0.105 mole) of sodium [(0- ethyl) -3 -acetyl-4-hydroxybenzyl] phosphonate, 25 0 milliliters of methanol, and 8.5 grams (0.0353 mole) of aluminum chloride hexahydrate in 100 milliliters of methanol. The stirred mixture was heated at reflux temperature for one hour. After cooling to room temperature, the white precipitate formed was collected on a Buchner funnel, washed with water and air dried to give 23.5 grams (82.8 percent yield) of a white compound which was characterized by its infrared spectrum as aluminum tris-[(O-ethyl)-3-acetyl 4 hydroxybenzyl]phosphonate, M.P. 300 C.

EXAMPLE 17 Zinc bis- (O-ethyl -3-acetyl-4-hydroxybenzyl] phosphonate Barium bis-[ O-ethyl -3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as that used in Examples 16 and 17 was used to treat a solution of 28 grams (0.1 mole) of sodium [(O-ethyl)-3-acetyl-4-hydroxybenzyl]phosphonate with a suspension of 12.2 grams of barium chloride dihydrate in milliliters of methanol. The suspension was filtered hot after two hours of refluxing and the filtrate evaporated under reduced pressure to give 24.0 grams (73.6 percent yield) of an off-white powdery product which was identified spectroscopically 7 as barium bis-[ (O-ethyl) -3-acetyl-4-hydroxybenzyl] phosphonate.

EXAMPLE l9 Cadmium bis-[ (O-ethyl)-3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as that used in Examples 16 and 17 was used to react a solution of 28 grams (0.1 mole) of sodium [(O-ethyl)-3-acetyl-4-hydroxybenzyl]phosphonate in 200 milliliters of methanol with 9.2 grams (0.05 mole) of cadmium chloride in 50 milliliters of methanol. A white powder weighing 24 grams (67.7 percent yield) was obtained and was identified by its infrared spectrum as cadmium bis-[(O-ethyl)- 3-acetyl-4-hydroxybenzyl]phosphonate, M.P. 255-265 C.

EXAMPLE 20 Tin bis- (O-ethyl)-3-acetyl-4-hydroxybenzyl] phosphonate Di- (n-dodecyl -3-acetyl-4-hydroxybenzyl phosphonate The same experimental procedure as used in Examples 1, 4, 7, and was used to react 58.6 grams (0.1 mole) of tri(-n-dodecyl)phosphite with 18.4 grams (0.1 mole) of 5'-chloromethyl-2'-hydroxyacetophenone. The molten mixture was kept at 150 C./ 0.5 mm. for 2 hours, then heated to approximately 180 C./0.5 mm. to remove dodecyl chloride. The residue was identified by its IR spectrum as di-(n-dodecyl)-3-acetyl 4 hydroxybenzyl phosphonate.

EXAMPLE 22 Sodium O-n-dodecyl -3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as that used in Examples 2, 5, 8, l1, and 14 Was used for the preparation of the above sodium salt. The compound was identified by its infrared spectrum.

EXAMPLE 23 Nickel bis-[ (O-n-dodecyl)-3-acetyl-4-hydroxybenzyl] phosphonate The same experimental procedure as that used in Examples 3, 6, 9, 12, and was used to prepare nickel bis-[(O-n-dodecyl)-3-acetyl 4 hydroxybenzyHphosphomate. The compound was identified by its infrared spectrum.

EXAMPLE 24 Similarly by the use of trioctadecylphosphite and 5'- chloromethyl-2-hydroxyacetophenone we obtained dioctadecyl-3-acetyl-4-hydroxybenzyl phosphonate. This compound was identified by its infrared spectrum.

EXAMPLE 25 By following the experimental procedure described in Examples 2, 5, 8, 11, and 14 we obtained sodium [(0- octadecyl -3-acetyl-4-hydroxybenzyl phosphonate.

EXAMPLE 26 The same experimental procedure as used in Example 23 was used to prepare nickel bis-[(O-dioctadecyl)-3- acetyl-4-hydroxybenzyl]phosphonate, which was obtained as a light green powder. Identification was made by means of its infrared spectrum.

EXAMPLE 27 Polypropylene resin In this example, the effect of the various metal phosphonate derivatives as identified in Samples No. 2 to 15 at two concentrations on a polypropylene film was determined. Fifteen such films were prepared as follows:

Sample No. 1, which contained parts unstabilized polypropylene, 0.1 part dilauryl thiodipropionate, and 1.0 part of a hindered phenol was fused in a Plasti-Corder blender at 175 C. for 5 minutes. The hindered phenol used was a product available under the trademark Irganox 1076, which is an alkyl ester of a carboxylic acid containing an alkylhydroxy phenyl group. This product is further identified in US. Pat. 3,330,859. The fused material was chopped and the resulting granules pressed into sheets or films about 25 mils thick using a Carver press at about C.

Samples No. 2 to 15 were prepared by the same experimental procedure as used in the preparation of Sample No. 1 except that the various metal phosphonate derivatives in the amounts indicated in Table 1 were added to each sample before fusion.

The resulting films were then used to determine the effectiveness of the metal derivatives as ultraviolet light absorbers by exposing the 15 films in chambers lighted with ultraviolet light and daylight fluorescent tubes for 575 hours. Each sample was exposed so thafsthe film protected a portion of a light-colored maple tongue blade. After 575 hours exposure, the wood exposed directly to the light and the wood exposed behind the film of Sample No. 1 showed considerable darkening. The experiments together with the results are summarized in Table 1.

TABLE 1.COMPARATIVE EFFECTIVENESS OF VARIOUS METAL [(O-ALKYL)-3-ACETYL-4-HYDROXYBENZYL1PHOSPHO- NATES AS ULTRAVIOLET LIGHT ABSORBERS IN POLYPROPYLENE FILM AFTER 575 HDURS EXPOSURE.

Parts phosphonate added per Condition of film Metal [(O-aIkyD-3-acetyl4- 100 parts Sample No. hydroxybenzyflphosphonate polypropylene UV protection Clarity Color Flexibility Control 0. 0 Nickel bis-[(O-ethyl) 0.5 o o. o. 1.0 Very slight. do.-- Yellow Cracked.

Tin bis-[(O-butyl) 0. 5 Good Opalescent S1. yellow Brittle. o 1.0 Very goo .do.-- do.- Do. Nickel bis-[(O-isooctyl) 0. 5 Very slight do D0. o 1. 0 Slight .-d0- Cracked. Nickel bis-[(O-isopropyl) 0. 5 do .do 0. d 1. 0 Good 0.. do Do. 0.5 Slight ..-.do Very 51. yellow. Do. 1. 0 Very good ..do S1. yellow Cracked less. 0.5 Slight do... Very 51. yellow Brittle. 1.0 Good-- ..do.-. ..do Do 0. 5 Very slight do.. S1 yellow Do.

1. light (1 Cracked- 9 EXAMPLE 28 Polyethylene resin In this example, the effect of the various metal phosphonate derivatives as identified in Samples 2 to 21 at two concentrations on a polyethylene film was determined. Twenty-one such films were prepared as follows:

Sample No. l was prepared by fusing 100 parts of polyethylene in a Plasti-Corder blender at 175 C. for minutes. The fused material was chopped and the resulting granules pressed into sheets or films about 25 mils thick using a Carver press at about 165 C.

Samples No. 2 to 21 were prepared by the same experimental procedure as used in the preparation of Sample No. 1 except that the various metal phosphonate derivatives in the amounts indicated in Table 2 were added to each sample before fusion.

The films were tested by exposure in a chamber lighted with ultraviolet light and daylight fluorescent tubes for a period of 575 hours. Each sample was exposed so that the film protected a portion of a light-colored maple tongue blade. After 575 hours exposure, the wood exposed directly to the light and the wood exposed behind the film of Sample No. 1 showed considerable darkening.

compositions of 50 percent solids identified as follows:- Medium soya alkyd resin, air-dried polyurethane resin, and a tung oil varnish at concentrations of 0, 0.5, and 1.0 percent by weight based on the total weight of the clear coating. These coatings were applied by brush to maple and Douglas fir wood surfaces. Two coats were applied allowing 24 hours between coats for drying. After the second coat had dried 24 hours, a small area of each coating on each of the wood surfaces was protected with a black tape and the coatings were exposed to ultraviolet light in an ultraviolet chamber.

After 50 hours exposure, the coatings that did not contain the phosphonate additives were badly discolored. Those coatings that contained 0.5 percent of the phosphonates were only slightly colored and the coatings containing 1.0 percent of the additives exhibited no discoloration.

The nickel phosphonates disclosed in Examples 23 and 26, especially when employed at a concentration equivalent to 1.0 percent based on the total weight of the resinous composition, exhibited excellent ultraviolet light absorbing properties.

The experiments reported in Examples 27 to 30 were repeated with the exception that sodium and potassium phosphonates were substituted for the various metal phos- TABLE 2.-COMPARATIVE EFFECTIVENESS OF VARIOUS METAL [(OALKYL)-3-ACETYL-4-HYDROXYBENZYL1PHOSPHO- NATES AS ULTRAVIOLET LIGHT ABSORBERS IN POLYETHYLENE FILM AFTER 575 HOURS EXPOSURE.

Parts phosphonate added per Condition of film Sample Metal [(O-alkyD-S-acetyl-4- 100 parts UV No. hydroxybenzyl]phosphonate polyethylene protection Clarity Color Flexibility 1 Control 0.0 None Opaque Brittle. 2 Nickel bis-[(O-ethyl) 0.5 .-...do Opalesce o. 3 do 1. 0 Very slight d No cracking. 4 Tin bis-[(O-butyl) 0.5 Slight Do. 5. o 1.0 Very good Do. 6.. Nickel bis-[(O-isooctyl) .1 0.5 None Cracked. 7.. o 1.0 Shght ..dO S1. yellow No cracking. 8.. Nickel bis-[(O-isopropyl 0.5 Very sli ht do do C ack d. 9 0 1.0 li h .(10 Yellow 0. 10 Barium bis-[(Oethyl) 0.5 Very li do White. No cracking. 11 do 1.0 Good do do Do. 12 Zinc bis-[(O-ethyl) 0.5 Sli ht do do D 13 do 1.0 Good do do Do. 14. Cadmium bis-[(O-ethyl) 0.5 None do do Cra k d. 15 I do 1. 0 Sli ht do do No c a king. 1 Tm bis-[(O-othyl) .1 0. None. -.do... Splotchy Brittle. 17.... .0 Very S ght -.do... Yellow-splotchy Cracked. 18 Aluminum tns-[(O-ethyl) 0.5 Slight do White Do. 19 1. 0 Very good -.do S1. yellow Less cracking. 20 Nickel bis-[(O-methyl 0.5 f d White. Brittle. 21 ..dO E1 -.do S1. yellow Slight cracking.

EXAMPLE 29 Polyvinyl chloride resin In this example, a resinous composition was prepared which contained on a weight basis 100 parts polyvinyl chloride resin, 50 parts dioctyl phthalate, 1 part barium stearate, and 1 part cadmium stearate. This composition was divided into 21 equal portions. One was used as a control, and to portions 2 to 20 was added the phosphonate disclosed in Examples 27 and 28 in such an amount that the weight percent of the phosphonate based on the weight of the polyvinyl chloride varied as follows: 0.5 and 1.0 percent.

These samples were laid over light-colored maple wood in a chamber lighted with fluorescent sunlight and ultraviolet light. Darkening of the wood occurred under the untreated plasticized polyvinyl chloride sample. No darkening occurred under the samples containing 0.5 and 1.0 part of the phosphonates after 575 hours of light exposure. Further, the samples with 0.5 and 1.0 part of the phosphonates exhibited less plasticizer surface exudation than the untreated sample after 575 hours of light exposure.

EXAMPLE 30 Coating compositions In this example, the phosphonates disclosed in Examples 27 and 28 were added to each of three different coating phonates used in those examples. Similar results were obtained.

In addition to their value as ultraviolet light absorbers for use with polymeric organic compositions, we have found that the phosphonates of our invention may be incorporated into consumer products such as face creams, lotions, and the like to protect the human skin from the detrimental effects of ultraviolet light.

Other materials which are stabilized by the compounds of the present invention include lubricating oil of the aliphatic ester type, e.g., di-(2-ethylhexyl)azelate, pentaerythritol tetracaproate and the like; animal and vegetable derived oils, e.g., linseed oil, fat, tallow, lard, peanut oil, cod liver oil, castor oil, palm oil, cottonseed oil, and the like; hydrocarbon material such as gasoline, both natural and synthetic, diesel oil, mineral oil, fuel oil, cutting fluids, waxes, resins and the like; fatty acids; varnishes, soaps, and the like.

We have found that these phosphonates, especially the aluminum, barium, and zinc, are eflective as heat stabilizers for polymeric organic compositions.

While particular embodiments of the invention have been described, it will be understood, of course, that the invention is not limited thereto since many modifications may be made thereto. It is, therefore, contemplated to cover by the appended claims any such modifications as fall within the true spirit and scope of the invention.

1 1 1 2 The invention having thus been described, what is 5. The composition of claim 1 identified as di-(n-buclaimed and desired to be secured by Letters Patent is: tyl)-3-acetyl-4-hydroxybenzyl phosphonate.

1. A composition having the formula: 6. The composition of claim 1 identified as di(isoctyl)- 3-acetyl-4-hydroxybenzyl phosphonate. 5 7. The composition of claim 1 identified as di-(n-dode- 0 cyl)-3-acetyl-4-hydroxybenzyl phosphonate. no l 8. The composition of claim 1 identified as dioctadecyl-3-acetyl-4-hydroxybenzyl phosphonate. =0 E 10 e References Cited UNITED STATES PATENTS wherein R is a straight or branched chain alkyl radical 3423487 1/1969 Scheuerer et a1 260946 containing from 1 to 18 carbon atoms.

2. The composition of claim 1 identified as dimethyl- 15 ANTON SUTTO Pnmary Exammer 3-acetyl-4-hydroxybenzyl phosphonate. US Cl.

3. The composition of claim 1 identified as diethyl-3- acetyl 4 hydroxybenzyl phosphonate 4468, DIG. 4; 25249.7, 49.8, 400; 260-45.7, 45.75

4. The composition of claim 1 identified as di(isopro- R, 45-75 45-75 429-9, 448 R, pyl)-3-acetyl-4-hydroxybenzyl phosphonate. 20 429 

